Spin‐State Modulation in FeII‐Based Hofmann‐Type Coordination Polymers: From Molecules to Materials

Abstract Spin crossover complexes that reversibly interconvert between two stable states imitate a binary state of 0 and 1, delivering a promising possibility to address the data processing concept in smart materials. Thus, a comprehensive understanding of the modulation of magnetic transition between high spin and low spin and the factors responsible for stabilizing the spin states is an essential theme in modern materials design. In this context, the present review attempts to provide a concise outline of the design strategy employed at the molecular level for fine‐tuning the spin‐state switching in Fe II ‐based Hofmann‐type coordination polymers and their effects on the optical and magnetic response. In addition, development towards the nanoscale architectures of HCPs, i. e ., in terms of nanoparticles and thin films, are emphasized to bridge the gap between the laboratory and reality.